This invention relates, in general, to a method for expanding corneal endothelial cells. More specifically, the invention relates to a method and a graft for treating problematic corneal endothelial cell decompensation in, for example, the reconstruction of corneal endothelium.
Corneal endothelial cells are a single layer of flat hexagonal cells that lie on a basement membrane, Descemet's membrane of the cornea, to form a pure cell sheet without any other cell types. The corneal endothelial cell is essential for maintaining corneal transparency. This function is dependent on endothelial regulation of stromal hydration, including the barrier and pump functions of the aqueous humor. Damage to the human corneal endothelial cells caused by intraocular surgery, glaucoma, trauma, or congenital corneal disease can result in irreversible corneal edema, at least in part because there is no or extremely low mitotic activity in the human corneal endothelial cell after birth, which leads to a gradual decrease in the cell population with age.
As corneal edema caused by damage of human corneal endothelial cells occurs, allograft posterior lamellar keratoplasty or penetrating keratoplasty is usually suggested as a remedy. One major concern of posterior lamellar keratoplasty or penetrating keratoplasty is that one donor cornea can only provide corneal endothelial layer replacement to one patient. Allograft rejection is another concern for penertrating keratoplasty. In addition, in many countries, the supply of donor corneas is insufficient.
Recently, it has been reported that the denuded amniotic membrane was used as a carrier for cultivated human corneal endothelial cell transplantation on the rabbit mode (Ishino Y. et al., Invest Ophthalmol Vis Sci. 2004; 45:800-806). However, according to the results, the amniotic membrane is not used for a substrate for ex vivo cell expansion.